File reading and writing
read_csv
# header= None
dataSet = pd.read_csv('ex1data1.txt', header=None, names=['Population', 'Profit'])
dataSet.head()
drawing
DataFrame.plot
resources: https://blog.csdn.net/brucewong0516/article/details/80524442
dataSet.plot(kind='scatter', x='Population', y='Profit')
plt.show()